1. Field of the Invention
The present invention relates to a method for packaging a Ball Grid Array (BGA), and more particularly to a method that uses a mold to package a BGA. With this arrangement and structure of the BGA, the production efficiency and the heat dissipation effect will increase dramatically.
2. Description of Related Art
Referring to FIG. 5, a conventional substrate (80) for packaging a Ball Grid Array is shown. The substrate (80) has slots (801) defined therein. A layer of tape (81) is provided around each of the slots (801) to secure the chip (not shown). After the chip is securely bonded to the substrate (80) by means of the gel on the tape (81), the process of wire bonding is then ready to be performed to complete the package. A shown in FIG. 6, each of the chips (82) securely bonded to the substrate (80) has a line of pads (820) securely mounted thereunder. The line of the pads (820) corresponds to one of the slots (801). Thereafter, metal wires (821) are bonded to connect the pads (820) with the substrate (80).
After the process of wire bonding is completed, the process of packaging is initiated. The aforementioned BGA components are packaged by gel (84) spread around each one of the chips (82) and filled in the slots (801), so as that the chips (82) are protected from damage by the solidified gel (84). Then solder balls (83) are provided under the substrate (80) to connect with the circuit of the substrate (80) so as to form a bare-chip Ball Grid Array.
The above description depicts the basic structure of the bare-chip BGA. However, such a structure suffers from a number of shortcomings:
1. low production efficiency
Since the distribution of the gel (84) is labor intensive, the time required to complete the BGA package is excessive, which results in low production efficiency.
2. insufficient protection
The bare-chip BGA chips (82) are only protected by the solidified gel (84). The protection to the chips (82) provided by the gel (84) is not sufficient to avoid damage to the chips (82).
3. low heat dissipation efficiency
The heat dissipation of this bare-chip BGA depends only on the exposed surfaces of the chips (82), which are in contact with the air. As for the dissipation of the extra heat, the bare-chip BGA will not be able to dissipate the heat effectively.
It is therefore an objective of the invention to provide a method for packaging the BGA and the structure of the substrate for accomplishing the packing.
The present invention intends to provide a method for packaging a BGA and the structure of the substrate to accomplish the packaging to mitigate and/or obviate the aforementioned problems.